The largest continent on Earth is running out of fresh water

In terms landmass and population, Asia dominates the rest of the globe.

But at least 1 billion of the continent's estimated 4.4 billion people could be facing extreme fresh water shortages in the near future, according to a study released by MIT researchers in the journal PLOS One.

If current trends in climate change and population growth continue, models show that a big swath of Asia could be facing a "high risk of severe water stress" — meaning water systems will be overtaxed relative to the number of people they serve — in as little as 35 years.

"It's not just a climate change issue," Adam Schlosser, one of the paper's co-authors, said in a statement. "We simply cannot ignore that economic and population growth in society can have a very strong influence on our demand for resources."

The researchers ran several scenarios that factored economics and industry into more traditional modeling around climate and birthrate.

But their models also accounted for economic drivers, like industrial use that will increase with growing populations.

The future of water is also a matter of distribution: "What happens upstream affects downstream basins," Schlosser noted. Basically, higher water use upstream means less water for people farther from the source.

The paper also suggests that the combined effects of economic and climate drivers are far more extreme than one or another.

There are caveats, though.

For one, the researchers assumed irrigation for crops would stay constant for the study, and that could easily change — for better (less usage) or worse (higher usage). The authors also note that, while they tried to capture some of the relationship between economies and water, they didn't account for any potential feedback that water scarcity could have on the economy — for example, cutbacks in industrial water usage as a result of drought.

Perhaps the biggest catch, though, might also be the greatest bright spot: This is an extreme picture of water scarcity in Asia, since the researchers' models assume humanity won't band together to slow global warming with considerable mitigation efforts.

Either way, the scientists warn that governments should adapt their water infrastructure to a drying world. Global and regional climates are already changing due to human activity. But with enough planning, we can hopefully lessen those effects for millions of people.